The 42-year-old woman was detained on Thursday in the Thisted area of northwest Denmark and was to be brought before a judge later on Friday, said Deputy Chief Superintendent Michael Kjeldgaard of the Mid and West Jutland Police.

“We are charging her with facilitating the illegal travel into the Schengen area of more than 600 people over a three-year period,” he said.

He said he presumed the smuggled people were still living illegally in Europe. “We do not know where they are — somewhere in the European area.”

Prostitution, often linked to human trafficking, was “not an aspect of this case,” Kjeldgaard said.

The accused woman had been living legally in Denmark, he added, declining to identify her further. If convicted, she could be jailed for up to eight years.

Created by a 1985 treaty to eliminate border controls, the Schengen zone now comprises 25 European countries with a population of more than 400 million.